Epicardial access system and methods

ABSTRACT

A method and apparatus are disclosed for a needle for gaining access to the pericardial cavity of a heart. The needle includes an elongate member (e.g. a main shaft) defining a lumen and a side-port in fluid communication with the lumen; a blunt atraumatic tip for delivering energy for puncturing tissue; and a guiding surface (e.g. a ramp) for directing a device (e.g. a guidewire) through the side-port. The method includes using the needle for tenting a pericardium and delivering energy for puncturing the pericardium, and advancing a guidewire or other device through the needle and into the pericardial cavity.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims the benefit of U.S.patent application Ser. No. 17/014,144, entitled “EPICARDIAL ACCESSSYSTEM AND METHODS,” and filed Sep. 8, 2020, which is a continuation ofand claims the benefit of U.S. patent application Ser. No. 15/754,030,entitled “EPICARDIAL ACCESS SYSTEM & METHODS,” and filed Feb. 21, 2018,now U.S. Pat. No. 10,779,883, issued Sep. 22, 2022, which is a nationalstage entry of International Application No. PCT/IB2016/055404, entitled“EPICARDIAL ACCESS SYSTEM & METHODS,” filed Sep. 9, 2016, which claimsthe benefit of U.S. Provisional Application No. 62/216,059, entitled“EPICARDIAL ACCESS SYSTEM AND METHODS,” and filed Sep. 9, 2015, whichare hereby incorporated by reference in their entireties.

TECHNICAL FIELD

This disclosure relates to the field of surgical needles. Morespecifically, this disclosure relates to surgical needles that useenergy for puncturing.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be readily understood, embodiments ofthe invention are illustrated by way of examples in the accompanyingdrawings, in which:

FIG. 1 , consisting of FIGS. 1A-1D, as well as detail views A-V1, A-V2,C1 and C2, is an illustration of a needle having a side-port inaccordance with an embodiment of the invention;

FIG. 2 , including detail views 2A-2C, is an illustration of a needlehaving a side-port in accordance with an alternative embodiment of theinvention;

FIG. 3 , consisting of FIGS. 3A-3H, is an illustration showing the stepsin a method of using a needle in accordance with an embodiment of theinvention;

FIG. 4 , consisting of FIGS. 4A-4F, is an illustration showing the useof ECG in accordance with an embodiment of the invention;

FIG. 5 is an illustration showing an enlarged view of a side-port inaccordance with an embodiment of the invention;

FIG. 6 , consisting of FIGS. 6A-6E, is an illustration showing the stepsin a method of using a needle in accordance with an alternativeembodiment of the invention; and

FIG. 7 , consisting of FIGS. 7A-7D, shows ECG readings in accordancewith an embodiment of the invention.

DETAILED DESCRIPTION

Minimally invasive access to the pericardial space is required fordiagnosis and treatment of a variety of arrhythmias and otherconditions. Access to the space may be initiated using a large diameter(for example, about 17Ga) Tuohy-style needle via the subxiphoidapproach. A guidewire (for example, about 0.032 inches (about 0.81 mm)in outer diameter) is then advanced to the heart through the needlelumen. After gaining access to the pericardial space, the operatorremoves the Tuohy needle then advances and secures a sheath (forexample, 8.5Fr) to facilitate use of treatment devices such as ablationand mapping catheters.

Mechanical puncture using large bore needles, as described above, isassociated with a high clinical complication rate. Although the stiffneedle provides some stability and some tactile feedback to the user,unwanted tissue damage is possible if the needle inadvertently puncturesor unintentionally lacerates tissue.

As a consequence of the challenges and uncertainties of using mechanicalpuncture for accessing the pericardial space, physicians may resort tocommon endocardial ablation in situations where epicardial ablation is apreferred treatment, such as ventricular tachycardias. New devices ormethods to improve the safety and predictability of gaining access tothe pericardial space would be of benefit.

The problem of improving the ease of use, safety, and predictability ofgaining access to the epicardium is solved, at least in part, by aneedle for gaining epicardial access, the needle having an elongatemember (e.g. a main shaft) defining a lumen and a side-port in fluidcommunication with the lumen; a blunt atraumatic tip for deliveringenergy for puncturing tissue; and a guiding surface (e.g. a ramp) fordirecting a device (e.g. a guidewire) through the side-port.

The present inventors have conceived, and reduced to practice,embodiments of such a medical device. Some embodiments of the needlehave a blunt tip of 17, 18 19, or 19.5 Ga. The blunt tip prevents anypremature mechanical puncture to the pericardium when pressed againstit. Also, a needle with a blunt tip provides better tactile feedbackthan a needle with a sharp tip. The side-port allows delivery ofcontrast agent and facilitates deployment of a device (e.g. a guidewire)through the needle to confirm access to the pericardial space.Physicians typically use fluoroscopy to check that the guidewire (orother device) is wrapped around the heart to confirm pericardial access.Physicians may also confirm access via tactile feedback which mayindicate incorrect needle position or obstruction. Physicians may alsodeliver contrast medium to confirm access and determine needle location.

In a first broad aspect, embodiments of the present invention comprise aneedle for use with a device and for gaining epicardial access, theneedle comprising: an elongate member which is comprised of a metal anddefines a lumen and a side-port with a proximal edge, the side-portbeing in fluid communication with the lumen; an insulation covering anoutside of the elongate member wherein a blunt tip of the needle iselectrically exposed to define an electrode for delivering energy forpuncturing tissue; a guiding surface extending from a side wall of theelongate member which is opposite to the side-port to define an end ofthe lumen, the guiding surface being configured for directing the devicethrough the side-port; and an insulation portion covering a proximalpart of the side-port defined by the elongate member to define anaperture which is smaller than the side-port, wherein the insulationportion is comprised of a polymer that is softer and less abrasive thanthe metal of the proximal edge.

As a feature of the first broad aspect, the needle is configured fordelivering energy through a metal side wall of elongate member to theelectrode. In some embodiments of this feature, the electrode hasgreater radiopacity than the elongate member. Some embodiments furthercomprise insulation on an inner surface of the elongate member adjacentto the side-port to reduce electrical leakage. Some embodiments includeinsulation on an inner surface of most or substantially all the elongatemember to reduce electrical leakage. In some embodiments of thisfeature, a part of the elongate member adjacent and distal of theside-port is electrically exposed to define an elongate member exposedportion. Some examples include a distal edge of the side-port is locatedat a distance of about 0.050 to 0.125 inches (about 1.27 to 3.18 mm)from an electrode distal tip. In some such examples, the distal edge ofthe side-port is located at a distance of about 0.090 inches (about 2.29mm) from the electrode distal tip.

In typical embodiments of the first broad aspect, the insulation portionis configured to reduce abrasive friction between the device and theproximal edge of the side-port as the device is advanced through theside-port. In typical embodiments, the lumen terminates at theside-port. Typical embodiments include the needle comprising a singleside-port operable for the device to travel therethrough. In someembodiments of the first broad aspect, the side-port is capsule-shaped.In some examples, a distal edge of the side-port includes a bevel. Insome such examples, the bevel includes a combination of rounded and flatportions.

In some embodiments of the first broad aspect, the proximal edge of theside-port is beveled. In some embodiments, the guiding surface has agenerally S-shaped surface.

As another feature of the first broad aspect, a distal end of theguiding surface is beveled, whereby the insulation portion which coversa proximal part of the side-port and the distal end of the guidingsurface facilitate the device being guided out of a side of the needleand in a forward direction when advanced out of the side-port.

In accordance with an embodiment of the present invention, a method isdisclosed for accessing a pericardial cavity, the method comprising thesteps of: (1) contacting a pericardium with a needle, (2) tenting thepericardium with the needle and delivering energy through a blunt tip ofthe needle, (3) puncturing the pericardium with the needle and injectinga contrast flow into a pericardial cavity through a side-port of theneedle, (4) advancing a guidewire through the needle and into thepericardial cavity, and (5) withdrawing the needle while leaving theguidewire in the pericardial cavity.

In accordance with an embodiment of the present invention, a method isdisclosed for accessing a pericardial cavity, the method comprising thesteps of: (1) contacting a pericardium with a needle, (2) tenting thepericardium with the needle and delivering energy through a blunt tip ofthe needle, (3) puncturing the pericardium with the needle and injectinga contrast flow into a pericardial cavity through a side-port of theneedle, (4) advancing a small diameter guidewire into the pericardialcavity, (5) withdrawing the needle and advancing a dilator to dilate thepuncture through the pericardium, (6) advancing a sheath over thedilator into pericardial cavity, (7) withdrawing the small diameterguidewire and advancing a relatively larger guidewire into thepericardial cavity, and (8) withdrawing the sheath.

In a further broad aspect, embodiments of the present invention are fora method having the steps of contacting a pericardium with a needle,using the needle for tenting the pericardium and delivering energy,using the needle for puncturing the pericardium and injecting a contrastflow into a pericardial cavity, advancing a guidewire (or other device)through the needle and into the pericardial cavity, and withdrawing theneedle while leaving the guidewire (or other device) in the pericardialcavity.

As features of this aspect, some embodiments of the method furtherinclude the steps of advancing a mapping catheter or some otherdiagnostic device, and/or advancing an ablation catheter or some othertreatment device, and/or placing leads or other medical devices.

With specific reference now to the drawings in detail, it is stressedthat the particulars shown are by way of example and for purposes ofillustrative discussion of certain embodiments of the present inventiononly. Before explaining at least one embodiment of the invention indetail, it is to be understood that the invention is not limited in itsapplication to the details of construction and the arrangement of thecomponents set forth in the following description or illustrated in thedrawings. The invention is capable of other embodiments or of beingpracticed or carried out in various ways. Also, it is to be understoodthat the phraseology and terminology employed herein is for the purposeof description and should not be regarded as limiting.

FIG. 1A shows a top view of a needle 20 having a side-port 22 inelongate member 21. FIG. 1B shows a side view of the same needle with aguidewire 50 extending out of side-port 22. The side-port of FIGS. 1Aand 1B is a slotted hole. The dimensions of the slot are dependent onthe needle gauge and guidewire outer diameter. Some embodiments ofneedle 20 are 17Ga, have a side-port width of about 0.036 inches (about0.91 mm), a radius of about 0.018 inches (about 0.46 mm), a slot lengthof about 0.180 inches (about 4.57 mm), and can accommodate deploymentand retraction of a 0.032 inches (about 0.81 mm) guidewire, and ofguidewires having a smaller outer diameter. Such an embodiment may alsoaccommodate, with a smaller clearance, a guidewire with an outerdiameter of 0.035 inches (about 0.89 mm). Guidewires used in thedisclosed method are typically comprised of spring stainless steel. Insome embodiments, the distal tip of the guidewire is made of nitinol toprovide a softer tip than steel. Some alternative embodiments comprisean insulated guidewire having a lubricous coating on the insulation.Embodiments of needle 20 typically have only a single side-port operablefor advancing a guidewire (or another device) therethrough.

While this disclosure, for explanatory purposes, focuses on the use ofneedle 20 with guidewires, other devices can be advanced through needle,for example, flexible devices operable to delivery energy or monitorphysiological variables.

The embodiment of the side-port 22 of FIG. 1A is a rounded slot or aslotted hole (i.e. capsule-shaped) having a constant side-port width.This configuration provides a flat wall with a minimal edge profile,thereby reducing the potential for generating debris when deploying orretracting a guidewire. Typically, side-port 22 and guidewire 50 areconfigured such that the clearance of the side-port 22 from theguidewire will be at least about 0.001 inches (about 0.025 mm). If usinga smaller outer diameter guidewire, the clearance will be greater.

Detail A-V1 and detail A-V2 show alternative views for cut-away line A-Aof FIG. 1A. Details A-V1 and A-V2 illustrate a guiding surface 24 (orramp) within side-port 22, which functions to guide an advancingguidewire 50 through side-port 22. The guiding surface embodiment may bestraight (e.g. detail A-V1) or curved (e.g. detail A-V2). The portion ofguiding surface 24 visible from external side-view (from outside of theneedle) has a length of about 0.020 inches (about 0.51 mm) for theembodiment of FIG. 1B. Please note, that while not all of the figuresshow a layer of insulation since it is not necessary for anunderstanding of the features illustrated by those figures, typicalembodiments of needle 20 include insulation.

Guidewire 50 is placed under a bending moment when exiting the sideport. To reduce this force, a bevel 26 (shown in FIG. 5 ) is located atthe distal edge of side-port 22. In some embodiments, a bevel 26 of 10degrees is located about 0.020 inches (about 0.51 mm) from the distaledge of side-port 22. Some such embodiments have been shown to beeffective in reducing the bending moment. In some embodiments the bevelis generally flat, while in other embodiments the bevel is rounded, andin yet further embodiments the bevel includes a combination of roundedand flat portions.

FIG. 5 is a cut-away view including distal tip 34 of needle 20, whereinelongate member 21 defines lumen 28, guiding surface 24, and side-port22. The embodiment of guiding surface 24 of FIG. 5 has a generallyS-shaped surface. In general, side-port 22 is located close to thedistal tip of the needle, which is advantageous for confirming theposition of distal tip 34 because it allows contrast fluid to bedelivered close to the needle's tip. In contrast, a device having aside-port that is relatively further away from the tip is more likely toencounter a situation where the side-port is still covered by tissueeven though the distal tip has punctured a layer of tissue. A side-port22 located close to the distal tip, in combination with the previouslydescribed bevel 26, also allows for a curved or ‘J’ tip wire extendedthrough side-port 22 to travel a short distance forward before curving,which prevents potential piercing of the epicardium with the wire tip.While a curved tip wire that easily bends or is floppy at the distal tipis advantageous for reducing unwanted tissue trauma, needle 20 may alsobe used with guidewire having a straight tip.

FIG. 1C is a cross-section showing a guidewire 50 that has been advancedthrough the lumen 28 and the side-port of needle 20. Enlarged sectionsC1 and C2 show guidewire 50 in contact with two different embodiments ofthe proximal edge 30 of side-port 22. Enlarged section C1 includes aproximal edge 30 having an approximately 900 angle. This angle is sharpenough to scrape a guidewire as it is advanced or retracted through theside-port, which may result in some debris creation. It is advantageousfor proximal edge 30 to be beveled (as shown, for example, in enlargedsection C2) to reduce debris generation when translating the guidewirethrough the needle. Some embodiments include a straight beveled edge, ora rounded bevel located about 0.020 inches (about 0.51 mm) from aproximal edge 30. In some such embodiments, these bevels have proveneffective in reducing debris formation.

FIG. 1D illustrates needle 20 with insulation 32 (typically a polymer)covering the needle shaft, leaving an area around side-port 22 exposed,and a distal tip area exposed to define an electrode 36 which may beused for channeling into and puncturing tissue. In some alternativeembodiments, insulation 32 is a ceramic.

Typical embodiments of needle 20 have an elongate member 21 (i.e. a mainshaft) comprised of 304, 316 or 317 stainless steel, and an electrode 36comprised of the same steel as the elongate member 21, with electrode 36being dome welded. Alternative embodiments of elongate member 21 arecomprised of other metals, including copper, titanium andnickel-titanium alloys, amongst others. In typical embodiments, energy(e.g. electricity) is delivered to electrode 36 through the metal sidewall of needle 20. In some alternative embodiments, the needle'selongate member 21 is comprised of a stiff polymer and electrical energyis delivered to electrode 36 through an electrically conductive wire.Some alternative embodiments have an electrode 36 comprised, at least inpart, of material more radiopaque than the elongate member such asplatinum, platinum and Iridium alloys, gold, or silver to provideradiopaque visibility under fluoroscopy to determine the location of theneedle's tip (i.e. the electrode has greater radiopacity than theelongate member). Such materials also improve reduction potential whencollecting ECG data. Round tipped electrodes and the use of such roundtipped electrodes for cutting tissue is described in U.S. Pat. No.8,192,425, which is incorporated-by-reference herein in its entirety.

In one specific embodiment of needle 20, side-port 22 in elongate member21 has a length of about 0.180 inches (about 4.57 mm), the distancebetween side-port 22 and electrode 36 is about 0.065 inches (about 1.65mm), electrode 36 has a hemispherical shape with a radius of about 0.025inches (about 0.64 mm), whereby distal tip 34 of needle 20 has an outerdiameter of about 0.050 inches (about 1.25 mm), and there is distance ofabout 0.090 inches (about 2.29 mm) between electrode distal tip 37 (FIG.1D) and side-port 22. In alternative embodiments, the distance betweenside-port 22 and electrode 36 is about 0.5 to 2 times the outer diameterof the needle tip; the length of side-port 22 depends on the innerdiameter of the needle and the outer diameter of the an intendedguide-wire, and ranges from about 0.1 to 0.2 inches, or about 2.54 to5.08 mm (about the equivalent of 3 to 6 times the outer diameter of a0.032 inch (about 0.81 mm) guidewire); the distance between electrodedistal tip 37 and side-port 22 ranges from about about 0.050 to 0.125inches (about 1.27 to 3.18 mm); and the electrode 36 has a size of about22 to 17 Gauge (about 0.028 inches (about 0.71 mm) to about 0.058 inches(about 1.47 mm)). The electrode is large enough to provide bumpersupport against heart tissue.

FIG. 1D also illustrates insulation portion 32 a, which covers aproximal part of side-port 22 to define an aperture 38 having a lengthof about 0.039 inches (about 0.99 mm). Aperture 38 is smaller thanside-port 22 (uncovered). If contrast fluid is delivered through needle20 under a constant lumen fluid pressure, the contrast will expel in anarrower stream and closer to the distal tip through an aperture 38 thanthrough a relatively longer side-port 22.

Insulation portion 32 a also reduces the amount of abrasive frictionbetween guidewire 50 and proximal edge 30 of the side-port. First, whileguidewire 50 can still rub against proximal edge 30 as it travelsthrough the side-port, insulation portion 32 a reduces the frictionalforces between the guidewire and proximal edge 30. Second, whenguidewire 50 travels through the side-port, it glides over insulationportion 32 a, which is comprised of a polymer that is softer and lessabrasive than the metal of the proximal edge 30. Insulation portion 32 afurther functions to direct an advancing guidewire forward, as to befurther explained below.

In addition, insulation portion 32 a reduces electrical leakage throughside-port 22. In typical embodiments of needle 20 the tubular metalshaft tube is not insulated, which allows some electricity to leak outof the metal immediately adjacent to the side-port (i.e. metal formingthe edge of the side-port), and some electricity to leak through fluidwithin the lumen and out of side-port 22. Insulation portion 32 a coverssome of the metal immediately adjacent the side-port to reduceelectrical leakage therefrom. Insulation portion 32 a also reduces theamount of fluid inside the lumen that is exposed to the environmentoutside the needle, thereby reducing electrical leakage through thefluid. Some alternative embodiments of needle 20 include insulation onan inner surface of the metal shaft tube in the area of the side-port(i.e. adjacent to) to reduce electrical leakage. Some other alternativeembodiments include insulation on an inner surface of most orsubstantially all the metal shaft tube to reduce electrical leakage.

Another feature of needle 20 illustrated in FIG. 1D is that insulation32 leaves a part of needle 20 adjacent to side-port 22 exposed to defineelongate member exposed portion 20 a. Another way to describe elongatemember exposed portion 20 a is that insulation 32 is trimmed back fromthe distal edge of side-port 22 to reduce the profile (or surface area)of the distal face of side-port 22. A reduced profile for the distalface allows a guidewire to exit the side-port at a reduced angle, i.e.,closer to needle 20. Furthermore, including elongate member exposedportion 20 a may help avoid a metallic guidewire adhering to insulationimmediately adjacent to the side-port if a physician inadvertentlyelectrifies the guidewire.

FIG. 2 illustrates an embodiment of needle 20 having a lubriciouscoating to enhance tactile feedback. FIGS. 2A to 2C show some of theuses of needle 20. FIG. 2A illustrates a guidewire 50 that has beenadvanced out of the side-port and is being advanced forwards. Guidewire50 is guided forward by insulation portion 32 a and bevel 26 of guidingsurface 24. In more detail, the insulation portion 32 a covers aproximal part of the side-port and a distal end of the guiding surface(or ramp) is beveled, whereby a device (e.g. a guidewire) is guided outof a side of the needle and in a forward direction when advanced out ofthe side-port. FIG. 2B illustrates contrast fluid injected using theside-port to create a contrast flow 52. FIG. 3 illustrates that a blunttip comprised of electrode 36 can be used for ECG monitoring andrecording. FIG. 4 , consisting of FIGS. 4A-4F, illustrates somemonitoring situations and the associated ECG signals. FIG. 7 ,consisting of FIGS. 7A-7D, shows ECG readings for different locations ofthe distal tip 34 of needle 20 within a pig to illustrate the advantageof ECG usage in identifying a puncture of a pericardium.

One method to fabricate a distal portion of a needle having thedescribed geometry is to weld a metal billet, placed inside the needlelumen and flush with the needle's distal tip, to the distal end of theneedle's metal shaft. The metal billet has a prefabricated guidingsurface produced using milling or electrical discharge machining (EDM),and the needle shaft has a prefabricated side-port.

Another method to fabricate a distal portion of a needle is to firstweld a solid metal billet flush with the distal tip of the needle'sshaft, and then form the side port slot and guiding surface with an EDMelectrode having a geometry corresponding to the side port and guidingsurface.

FIG. 3 is an illustration showing an eight step method of using fivedevices, including a needle 20 disclosed herein. FIG. 3A shows a step 1of contacting a pericardium 70 with needle 20. The heart is typicallyapproached using a subxiphoid approach. Step 2 (FIG. 3B) includestenting pericardium 70 with the needle and delivering energy (shown inbroken line) through the blunt tip of needle 20. Step 3 (FIG. 3C)includes puncturing the pericardium 70 with the needle and injecting acontrast flow 52 into pericardial cavity 72 through a side-port ofneedle 20. In this example of the method, needle 20 is not touchingmyocardium 74, while in alternative embodiments, needle 20 touches butdoes not tent the myocardium 74. FIG. 3D illustrates step 4, advancing asmall diameter guidewire 54 through the side-port and into thepericardial cavity 72. After the small diameter guidewire 54 isadvanced, the method further includes a step 5 (FIG. 3E) of withdrawingneedle 20 and advancing dilator 56 to dilate the puncture throughpericardium 70. Sheath 58 may be advanced with dilator 56 or the sheathmay be advanced afterwards to arrive at the illustration of FIG. 3E.Once the puncture is dilated, the method includes step 6 of advancingsheath 58 over the dilator into pericardial cavity 72 to arrive at theillustration of FIG. 3F. Step 7 includes withdrawing small diameterguidewire 54 and advancing guidewire 50 into pericardial cavity 72 (FIG.3G). Step 8 (FIG. 3H) includes withdrawing the sheath, and leaving theguidewire 50 in pericardial cavity 72. In some embodiments guidewire 50has a diameter of about 0.032 inches (about 0.813 mm) and small diameterguidewire 56 has a diameter of about 0.018 inches (about 0.46 mm). Insome alternative embodiments, small diameter guidewire 56 has a diametersmaller than 0.018 inches (about 0.46 mm). Once guidewire 50 has beenadvanced into pericardial cavity 72 to provide access, other steps mayinclude advancing a mapping catheter or some other diagnostic device,advancing an ablation catheter or some other treatment device, orplacing leads or other medical devices.

FIG. 6 is an illustration showing a five-step method of using twodevices, needle 20 and guidewire 50. Step 1 (FIG. 6A) includescontacting a pericardium 70 using needle 20. Step 2 (FIG. 6B) includestenting pericardium 70 with the needle and delivering energy (shown inbroken line) through the blunt tip of needle 20. Step 3 (FIG. 6C)includes puncturing the pericardium 70 with the needle and injecting acontrast flow 52 into pericardial cavity 72 through a side-port ofneedle 20. FIG. 6D illustrates a step 4 of advancing a guidewire 50through the needle and into pericardial cavity 72. After the guidewire50 is advanced, the method further includes a step 5 of withdrawingneedle 20 while leaving guidewire 50 in pericardial cavity 72 to arriveat the illustration of FIG. 6E. In some embodiments guidewire 50 has adiameter of about 0.032 inches (about 0.813 mm). As with the abovemethod, once guidewire 50 has been advanced into pericardial cavity 72to provide access, other steps may include advancing a mapping catheteror some other diagnostic device, advancing an ablation catheter or someother treatment device, or placing leads or other medical devices forexample at the epicardium. Guidewire used in the two above describedmethods may have a straight tip or a curved tip.

The embodiments of the invention described above are intended to beexemplary only. The scope of the invention is therefore intended to belimited solely by the scope of the appended claims.

It is appreciated that certain features of the invention, which are, forclarity, described in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures of the invention, which are, for brevity, described in thecontext of a single embodiment, may also be provided separately or inany suitable subcombination.

Although the invention has been described in conjunction with specificembodiments thereof, it is evident that many alternatives, modificationsand variations will be apparent to those skilled in the art.Accordingly, it is intended to embrace all such alternatives,modifications and variations that fall within the broad scope of theappended claims. All publications, patents and patent applicationsmentioned in this specification are herein incorporated in theirentirety by reference into the specification, to the same extent as ifeach individual publication, patent or patent application wasspecifically and individually indicated to be incorporated herein byreference. In addition, citation or identification of any reference inthis application shall not be construed as an admission that suchreference is available as prior art to the present invention.

What is claimed is:
 1. A needle for use with a guidewire for gainingepicardial access, the needle comprising: an elongate member which iscomprised of a metal and defines a lumen and a side-port having aproximal edge, the side-port being in fluid communication with thelumen; an insulation covering an outside of the elongate member whereina blunt tip of the needle is electrically exposed to define an electrodefor delivering energy for puncturing tissue, the insulation including aninsulation portion extending past the proximal edge of the side-port;and a guiding surface extending from a side wall of the elongate memberopposite the side-port, the guiding surface configured to direct theguidewire from the lumen and out the side-port.
 2. The needle of claim1, wherein the needle is configured to deliver energy through a metalside wall of elongate member to the electrode.
 3. The needle of claim 2,wherein the electrode has greater radiopacity than the elongate member.4. The needle of claim 1, wherein the insulation portion is configuredto reduce abrasive friction between the device and the proximal edge ofthe side-port as the device is advanced through the side-port.
 5. Theneedle of claim 2, further comprising insulation on an inner surface ofthe elongate member adjacent to the side-port to reduce electricalleakage.
 6. The needle of claim 2, further comprising insulation on aninner surface of most or substantially all the elongate member to reduceelectrical leakage.
 7. The needle of claim 2, wherein a part of theelongate member adjacent and distal of the side-port is electricallyexposed to define an elongate member exposed portion.
 8. The needle ofclaim 1, wherein the side-port is capsule-shaped.
 9. The needle of claim1, wherein a distal edge of the side-port includes a bevel.
 10. Theneedle of claim 9, wherein the bevel includes a combination of roundedand flat portions.
 11. The needle of claim 1, wherein the proximal edgeof the side-port is beveled.
 12. The needle of claim 1, wherein theguiding surface has a generally S-shaped surface.
 13. The needle ofclaim 1, wherein a distal end of the guiding surface is beveled, wherebythe insulation portion which covers a proximal part of the side-port andthe distal end of the guiding surface facilitate the device being guidedout of a side of the needle and in a forward direction when advanced outof the side-port.
 14. A needle for use with a guidewire for gainingepicardial access, the needle comprising: an elongate member which iscomprised of a metal and defines a lumen and a side-port having aproximal edge, the side-port being in fluid communication with thelumen; an insulation covering an outside of the elongate member whereina blunt tip of the needle is electrically exposed to define an electrodefor delivering energy for puncturing tissue, the insulation including aninsulation portion extending past the proximal edge of the side-port;and a guiding surface extending from a side wall of the elongate memberopposite the side-port, the guiding surface configured to direct theguidewire from the lumen and out the side-port; wherein a distal end ofthe guiding surface is beveled so as to direct the guidewire in a distaldirection upon exiting the side-port.
 15. The needle of claim 14,wherein the needle is configured to deliver energy through a metal sidewall of elongate member to the electrode.
 16. The needle of claim 14,wherein the insulation portion is configured to reduce abrasive frictionbetween the device and the proximal edge of the side-port as the deviceis advanced through the side-port.
 17. The needle of claim 15, furthercomprising insulation on an inner surface of the elongate memberadjacent to the side-port, the insulation configured to reduceelectrical leakage.
 18. The needle of claim 14, wherein the side-port iscapsule-shaped.
 19. The needle of claim 14, wherein a distal edge of theside-port includes a bevel.
 20. The needle of claim 19, wherein thebevel includes a combination of rounded and flat portions.